1. Field of the Invention
The present invention generally relates to communication systems and more particularly to the routing of communications between users of mobile communication devices.
2. Related Art
Conventional unlicensed mobile access (UMA) communication systems can provide users with the ability to access cellular services through unlicensed spectrum technologies. For example, users of appropriately configured UMA-compatible mobile phones may utilize Global System for Mobile (GSM) and General Packet Radio Services (GPRS) mobile services through wireless local area networks (WLANs) supporting various unlicensed mobile communication standards such as IEEE 802.11 or Bluetooth™.
In conventional UMA systems, communications are routed from a user's mobile station (for example, a UMA-compatible mobile phone) through a WLAN to a broadband Internet Protocol (IP) network which may interface with a UMA network controller (UNC). The UNC may in turn interface with a mobile switching center (MSC) capable of providing voice and SMS services and routing calls to the Public Switched Telephone Network (PSTN). The MSC is also capable of routing the communications to an alternate radio access network (RAN) of a cellular service provider. The UNC may additionally interface to a Serving GPRS Support Node (SGSN) for routing packets to a Gateway GPRS Support Node (GGSN) (which is capable of providing IP services), or routing the communications to an alternate RAN of a cellular service provider. UMA systems may also support seamless handover of cellular voice calls, Short Message Service (SMS) messages, and GPRS based packet services between the RAN and the WLAN.
Security is a dominant concern for providers of UMA-based communications. Conventional UMA configurations typically employ a hub-and-spoke security implementation whereby UMA clients (e.g., phones) establish a long-lived IP Security (IPSec) tunnel to the cellular service provider over which all communications including signaling, voice communications, and data communications are sent. A security gateway may be provided in the UNC to authenticate users, encrypt communications, and perform other relevant conventional security features. Alternatively, a security gateway may be deployed independently of a UNC and an IP network used to route communications between the UNC and the security gateway.
Unfortunately, in circumstances where UMA clients are located in close proximity to each other, such security implementations can lead to inefficiencies. For example, if two UMA clients accessing a common WLAN wish to communicate with each other, a conventional security implementation would typically require the routing of their associated communications from one UMA client through the WLAN and IP network to the UNC where security operations would be performed, to the MSC where voice services are executed, and back through the IP network and WLAN network to the other UMA client. In such a configuration, MSC ports are still provisioned and consumed by such UMA-to-UMA communications. Moreover, bandwidth restrictions on IP networks may limit the number of UMA users which may be simultaneously supported through such a security implementation.
Nevertheless, the use of such co-located intra-UMA communications is becoming increasingly likely. In this regard, cellular service plans often include provisions for unlimited calls between particular user groups. Typically, the user groups who benefit from such packages are families. Hence, multiple users within the same unlimited user group may be frequently located in the same residence.
Other UMA communication inefficiencies may occur where UMA users desire to interact with various IP-based resources available on the Internet. For example, GPRS data communications from UMA users typically must be routed from the user's WLAN through the IP network to the security gateway of the UNC. The UNC then passes communications on to the SGSN which routes communications to a GGSN which then routes communications to the Internet. Unfortunately, because the UMA communications must be routed through the security gateway of the UNC, they are not permitted to be routed directly to the Internet through the IP network connected to the WLAN. As a result, the security implementation defined by UMA may inhibit the optimal routing of IP services.
Accordingly, there is a need for an improved UMA-based security implementation that overcomes the deficiencies discussed above.
Like element numbers in different figures represent the same or similar elements.